Leakage of hot combustion gases and/or cooling flows between turbine components generally causes reduced power output and lower efficiency. For example, the hot combustion gases may be contained within the turbine by providing pressurized compressor air around the hot gas path. Leakage of high pressure cooling flows into the hot gas path thus may lead to detrimental parasitic losses. Overall efficiency thus may be improved by blocking the leakage locations while providing cooling flow only as required.
For example, current gas turbines may use cloth seals between adjacent stator components to limit the leakage of cooling flows therebetween. Such cloth seals may have a woven wire mesh cloth layer wrapped around a metal shim with a curved “shepherds hook” on either side. Manufacturing variations, however, involved in creating the shepherds hook and the overall cloth seal may impact the leakage rate therethrough. Even lower leakage rates may be achieved by using thin metal shims between the stator components. To date, however, the use of such thin metal shims in heavy duty gas turbines has not been feasible given concerns with robustness as well as manufacture and assembly issues with such seals.
There is thus a desire for an improved seal assembly for use between stator components and other components in a heavy duty gas turbine engine. Such a seal assembly may be substantially temperature resistant, wear resistant, and flexible so as to provide adequate sealing with a robust component lifetime.